From c39b98dd021f58d8209037b1297b7c3b1376fba3 Mon Sep 17 00:00:00 2001
From: Garen Tyler <garentyler@garen.dev>
Date: Sun, 12 Nov 2023 13:34:46 -0700
Subject: [PATCH] proc_mapstacks

---
 kernel/proc.c                                   | 17 -----------------
 .../rustkernel/src/arch/riscv/virtual_memory.rs | 15 ++++++++++++---
 kernel/rustkernel/src/proc/process.rs           |  1 -
 3 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/kernel/proc.c b/kernel/proc.c
index 11fc6f5..b4085d3 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -16,23 +16,6 @@ extern void forkret(void);
 // must be acquired before any p->lock.
 struct spinlock wait_lock;
 
-// Allocate a page for each process's kernel stack.
-// Map it high in memory, followed by an invalid
-// guard page.
-void
-proc_mapstacks(pagetable_t kpgtbl)
-{
-  struct proc *p;
-  
-  for(p = proc; p < &proc[NPROC]; p++) {
-    char *pa = kalloc();
-    if(pa == 0)
-      panic("kalloc");
-    uint64 va = KSTACK((int) (p - proc));
-    kvmmap(kpgtbl, va, (uint64)pa, PGSIZE, PTE_R | PTE_W);
-  }
-}
-
 struct proc *allocproc(void);
 
 // a user program that calls exec("/init")
diff --git a/kernel/rustkernel/src/arch/riscv/virtual_memory.rs b/kernel/rustkernel/src/arch/riscv/virtual_memory.rs
index ccae751..080f850 100644
--- a/kernel/rustkernel/src/arch/riscv/virtual_memory.rs
+++ b/kernel/rustkernel/src/arch/riscv/virtual_memory.rs
@@ -1,6 +1,6 @@
 use super::{
     asm,
-    mem::{make_satp, pte2pa},
+    mem::{make_satp, pte2pa, kstack},
     plic::PLIC,
     power::QEMU_POWER,
 };
@@ -17,7 +17,6 @@ use crate::{
         kalloc::{kalloc, kfree},
         memmove, memset,
     },
-    proc::process::proc_mapstacks,
 };
 use core::ptr::{addr_of, addr_of_mut, null_mut};
 
@@ -34,6 +33,9 @@ pub static mut KERNEL_PAGETABLE: Pagetable = null_mut();
 /// Make a direct-map page table for the kernel.
 pub unsafe fn kvmmake() -> Pagetable {
     let pagetable = kalloc() as Pagetable;
+    if pagetable.is_null() {
+        panic!("kalloc");
+    }
     memset(pagetable.cast(), 0, PAGE_SIZE as u32);
 
     // QEMU test interface used for power management.
@@ -105,7 +107,14 @@ pub unsafe fn kvmmake() -> Pagetable {
     );
 
     // Allocate and map a kernel stack for each process.
-    proc_mapstacks(pagetable);
+    for i in 0..crate::NPROC {
+        let page = kalloc();
+        if page.is_null() {
+            panic!("kalloc");
+        }
+        let virtual_addr = kstack(i) as u64;
+        kvmmap(pagetable, virtual_addr, page as u64, PAGE_SIZE as u64, PTE_R | PTE_W);
+    }
 
     pagetable
 }
diff --git a/kernel/rustkernel/src/proc/process.rs b/kernel/rustkernel/src/proc/process.rs
index 7a17b01..3ce7323 100644
--- a/kernel/rustkernel/src/proc/process.rs
+++ b/kernel/rustkernel/src/proc/process.rs
@@ -46,7 +46,6 @@ extern "C" {
     pub fn userinit();
     pub fn forkret();
     pub fn wait(addr: u64) -> i32;
-    pub fn proc_mapstacks(kpgtbl: Pagetable);
 }
 
 pub static NEXT_PID: AtomicI32 = AtomicI32::new(1);